In vivo calcium imaging is a common strategy used to visualize neural network activity. GCaMP, a genetically encoded calcium indicator, fluoresces upon binding to intracellular calcium to provide a measurable readout of neural activation. However, expression of calcium indicators is not specific to the cell body of the neuron, and molecules such as GCaMP also can be found in neurites. Moreover, the cell body of one neuron may be covered by neurites of nearby neurons. Thus, it is currently difficult to interpret whether the signal emitted from GCaMP originates from the cell body of one neuron or from the processes of neighboring neurons. This imprecise signal, called neuropil contamination, is a hindrance to detecting true neuronal spikes. This technology, called SomaGCaMP, is a GCaMP molecule with a modified sequence that specifies its localization to the cell body of neurons to enable single-cell detection of neural activation.